In April, the U.S. Environmental Protection Agency took long-delayed action to regulate extremely toxic chemicals under the Toxic Substances Control Act. Yesterday, the U.S. Chamber of Commerce submitted a letter to regulatory czar Cass Sunstein, asking him to “[s]uspend the consideration and initiation of all TSCA§5(b)(4) listings” because “it appears EPA lacks the sound regulatory science needed to meet the statutory threshold for a restriction or ban of the targeted chemicals.”